ABSTRACT
The mitogenic response of lymphocytes in mouse spleen cell culture to the action of Salmonella typhi lipopolysaccharide (LPS) and Vi-antigen under different experimental conditions has been studied. The density of the culture has been shown to influence the activation of lymphocytes with Vi-antigen. Thus, macrophages stimulate mitogenesis at the concentration of lymphocytes equal to 1.0-1.2 X 10(6) cells/ml and suppress it when this concentration increases tenfold. The method used for the purification of cell suspension from adhering cells has been shown to influence the level of the mitogenic response of lymphocytes. The cultures, purified from macrophages by filtration through a column packed with cotton wool, have been found to respond to the mitogenic doses of LPS 7-8 times weaker than those purified by adhesion onto plastic. Background and mitogen-induced inclusion of 3H-thymidine into lymphocytic DNA varies in accordance with the presence of adhering cells. For this reason, in the evaluation of the influence of macrophages on mitogenesis it is expedient to consider not only the stimulation index, but also the absolute inclusion of thymidine into cells.
Subject(s)
Antigens, Bacterial/immunology , Antigens, T-Independent/immunology , Lipopolysaccharides/pharmacology , Lymphocytes/cytology , Mitosis/drug effects , Polysaccharides, Bacterial , Salmonella typhi/immunology , Animals , Cell Adhesion , Cells, Cultured , Lymphocyte Activation/drug effects , Lymphocytes/immunology , Macrophages/immunology , Mice , Mice, Inbred CBA , Spleen/immunologyABSTRACT
The treatment with concanavalin A (5 micrograms/ml) of mouse lymphocytes containing 70-72% of T cells entails an increase in the activity of acid phosphatase and a decrease in the activity of N-acetyl-beta-glucosaminidase. These changes were detectable 15 h after lymphocyte incubation with Con A. After 24 h of incubation acid phosphatase activity rose 2-fold whereas that of N-acetyl-beta-glucosaminidase dropped 45-50%. Possible mechanisms of these changes are discussed.
Subject(s)
Acetylglucosaminidase/blood , Acid Phosphatase/blood , Concanavalin A/pharmacology , Hexosaminidases/blood , Lymphocytes/enzymology , Animals , Lymphocytes/drug effects , Mice , Mice, Inbred CBAABSTRACT
Homology between DNAs of some orthopoxviruses: vaccinia, neurovaccinia, cowpox, ectromelia, variola and white-pox was studied. By the method of molecular hybridization of labelled virion DNAs of the viruses studied with an excess of unlabelled vaccinia DNA and further treatment of the hybridized products by the single-stranded-specific nuclease S1, it was shown that the concentration of unlabelled vaccinia virus DNA, converting 50% of homologous labelled DNA into a hybrid, converted under similar experimental conditions into a hybrid 50% of labelled neurovaccinia virus DNA, 48% of white-pox virus DNA, 43% of variola virus DNA, about 30% of cowpox virus DNA and 27% of ectromelia virus DNA. Based on the quantitative data obtained the relationship between viruses of this subgroup and the possible origin of vaccinia virus is discussed.
